Augment obs_refrac structure to hold tdry

[Ian Culverwell]

Hans Gleisner at DMI remarks:

Just to clarify the issue with adding tdry to the Fortran structured 
variable used in forward modelling:

The subroutine for doing 1D forward modelling to refractivity is 
ropp_fm_refrac_1d( state, obs_refrac ) where TYPE(State1dFM)::state  
and TYPE(Obs1dRefrac)::obs_refrac

The subroutine for doing forward modelling to dry temperatures is
currently ropp_fm_tdry_1d( state, obs_refrac, tdry ) where 
REAL(wp)::tdry .

It would be practical to include tdry as a part of the Obs1dRefrac 
structure. It sits on the same vertical levels as refractivity, so 
there is no need to change anything else in the Obs1drefrac 
structure.

In that way, we would not have to define an explicit variable tdry.

Sounds fairy nuff to me.

[Ian Culverwell]

Bumping to ROPP10.0.

[Ian Culverwell]

Defer to ROPP-11.0.

[Ian Culverwell]

Rolling over to ROPP-12.0.